Plant growth modifier and a process for preparation thereof

ABSTRACT

WHEREIN X and Y stand for a member selected from Cl-, HO-, CH3Oand CH3CO- and n and m stand for an integer of 0 to 3. A plant growth modifier comprising as an active ingredient at least one compound selected from the group consisting of compounds (I), (II) and (III) expressed by the following formulae:

Hashimoto et al.

[ Nov. 4, 1975 PLANT GROWTH MODIFIER AND A PROCESS FOR PREPARATIONTHEREOF Inventors: Tohru Hashimoto, Musashino; Akira Kawarada; SachikoTamura, both of Tokyo, all of Japan Assignee: Rikagaku Kenkyusho, JapanFiled: Feb. 12, 1973 Appl. No.1 331,498

References Cited UNITED STATES PATENTS 5/1971 Sheens 71/122 OTHERPUBLICATIONS Chemical Abstracts, Vol, 67, C01. 43877(s) 1967. ChemicalAbstracts, Vol. 68, C01. 694216) 1968.

Pn'mdry ExaminerGlennon H. Hollrah 57] ABSTRACT A plant growth modifiercomprising as an active ingredient at least one compound selected fromthe group consisting of compounds (I), (II) and (III) expressed by thefollowing formulae:

X11 XII CH 2 l (II) CH2 l'll m XII (III) wherein X and Y stand for amember selected from Cl, 110-, CH O- and CH CO and n and m stand for aninteger of 0 to 3.

17 Claims, No Drawings PLANT GROWTH MODIFIER AND A PROCESS FORPREPARATION THEREOF The present invention relates to a novel growthmodifier for plants. Particularly the present invention relates to anovel plant growth modifier useful for controlling growth andgermination of seeds, sprouting or budding of plants, for recuring ill'plants, and for regulating dormant stage of seeds, tubers, corms; bulbsand buds.

Various research works have heretofore been made on plant growthmodifiers, and a great number of compounds have been proposed as plantgrowth modifiers, such as maleic hydrazide, abscisic acid, AMOll6l8,PhosphonD, B-Nine. etcl Further, it isknown that irracliation with y-rayis effective for artificially prolonging the dormant stage. However,none of plant growth modifiers comprising active ingredients such asclaimed in this invention have heretofore been known in the art.

We have made extensive research with a view to providing novel plantgrowth controlling agents and found that compounds expressed by thefollowing general formulae (I), (II) and (III) are highly effective formodifying growth of plants. and inducing or prolonging the dormancy inplants. Based on the foregoing finding, we have now completed plantgrowth modifiers of this invention.

Therefore the present invention relates to a plant growth modifiercomprising as an active ingredient at least one compound selected fromthe group consisting of compounds (I), (II) and (III) expressed by thefollowing formulae:

(III) wherein X and Y stand for a member selected from Cl, HO, CH O andCH CO- and n and in stand for an integer of 0 to 3.

Plant growth modifiers of this invention make it possible toartificially modify the intrinsic habitudes of various plants. Forinstance, they can control the budding of plants or excessive growth ofplants in growing period, and they make it possible to dwarf plants in ahealthy state. Further, if seeds, tubers, bulbs and buds lying dormantare treated with the plant growth modifiers of this invention, theperiod of the dormant stage thereof can be preferably prolonged, and ifthey are treated when they are going to initiate growth, it is pos sibleto'drive them into dormancy again. Thus, the active ingredient of thisinvention can be applied at a suit able concentration according to anappropriate method and it is possible to modify or retard the growth andgermination in various plants. For instance, when the plant growthmodifier of this invention is applied to growing plants such asChrysanthemums, dahlias, begonias, cosmoses and the like, the elongationof stalks is suppressed in the healthy state to give dwarf plants,whereby the appreciation value of these plants can be increased.Further, when the plant growth modifier of this invention is applied torice plants, wheat plants and the like, excessive growth of halm isinhibited and a tendency of these plants to fall down on earth when theycome into ears can be reduced, whereby either the crop or quality of thecrops can be greatly improved. Moreover, when corms, bulbs or tubers ofonion, garlic, potato, tulip and the like are treated with the plantgrowth modifier of this invention, the period of the dormant or restingstage can be prolonged to maintain freshness. in these plants for a longtime and increase values as foods or seeds. In addition, if mulberrytrees are treated with the modifier of this invention when late frostingthreatens to come before the initiation of germination, they can beprevented from damage by the frost. Thus various advantages can beobtained by application of the plant growth modifiers of this invention.

Compounds expressed by the above general formulae (I), (II) and (IIIwhich are used as active ingredients of plant growth modifiers of thisinvention will now be illustrated. These compounds (1), (II) and (III)are respectively bibenzyl, phenanthrene and dihydrophenanthrenecompounds which may optionally have such substituents as Cl, HO. CH;;O.These compounds are prepared from benzaldehyde and phenylacetic acid ortheir substituted derivatives, and a vari V ety of bibenzyl, andphenanthrene compounds can be obtained depending on the kind ofsubstituents bonded to such starting compounds.

Methods of preparing these compounds (I), (II) and (III) will now beillustrated by reference to hydroxymethoxy-bibenzyl as a typicalinstance of the compound (l), hydroxy-methoxy-phenanthrene as a typicalinstance of the compound (II) and hydroxy-methoxycompoun'dj'isacetylated by heating in a nitrogen gas atmosphere in the presence ofquinoline and copper chromite, acetoxy-methoxy-stilbene is formed. Then,

this stilbene derivative is catalytically reduced and hydrolyzed with analkali to obtain 3-hydroxy-5-mcthoxybibenzyl.

By similar procedures there may readily be obtained bibenzyl compoundssuch as 2,2'-dihydroxy-3,5-dimethoxybibenzyl,3,4'-dihydroxy-4.5-dimethoxybibenzyl, 4.6-dihydroxy-3-acetylbibenzyl,2.4-dihydroxybibenzyl, 3.5.3,5-tetrachloro-2,2'-dihydroxybibenzyl. 3,3,-5-trihydroxy-4-methoxybibenzyl, 3.3'-dihydroxy-5- methoxybibenzyl, etc.

Methods of preparing phenanthrenes expressed by the above generalformulae (II) and (III) will now be described. Acetoxy-methoxy-stilbenementioned above with respect to the preparation of compounds (I) isdissolved in ethanol, and iodine is added to the solution. When theresulting solution is irradiated, the ring-closure is caused to occur bythe photo-chemical reaction and acetoxy-methoxy-phenanthrene is formed.Hydrolysis of this compound gives hydroxy-methoxyphenanthrene. When thiscompound is catalytically reduced, hydroxy-methoxy9, lO-dihydrophenanthrene is obtained.

By similar procedures there can easily be obtained2,4-dimethoxy-o-hydroxyphenanthrene, 4-hydroxy-2,6,7-trimethoxyphenanthrene. 2,6-dihydroxy-3,4,7-trimethoxyphenanthrene, 4.6.7-trihydroxy-2.3-dime' thoxyphenanthrene,2.4-dimethoxy-6-hydroxyphenanthrene, fi-chloro-9-acetylphenanthrene, 7-hydroxy-2,6-diacetyl-9, l 0-dihydrophenanthrene, 2,3,5,7-tetrahydroxy-9,l Odihydrophenanthrene, 4.7- dihydroxy-2 ,3 ,6-trimethoxy-9, 1O-dihydrophenanthrene, 4 ,7-dihydroxy-2 .6-dimethoxy-9, lO-dihydrophenanthrene, etc.

Among compounds exemplified above. 2,2-dihydroxy-3,S-dimethoxybibenzyland 3,3'-dihydroxy-5- methoxybibenzyl are novel substances heretoforeunknown in the art. Alternately, these compounds can be isolated fromnatural sources, for instance from a subterranean or terrestrial tubersof yarn (Diosc'orea balm ms Decne.) or other organs in the dormantstage. An example of the method of obtaining these novel compounds willbe described below.

The terrestrial tubers of yarn (Discoreu batams Decne.) is immersed inan organic solvent such as methanol, ethanol and acetone or groundtogether with such solvent, to recover extract. The extract isconcentrated under reduced or atmospheric pressure to remove the solventused for extraction. Instead of the above organic solvent, waterincorporated with 0.05 0.l7c of Tween 20 or Tween 80 (surfactantmanufactured by Atlas Chemical Co., U.S.A.) can be used as an extractionsolvent. The resulting extract, as it is or after adjust pH to 6.5 8.0,is shaken with ethyl ether, isopropyl ether. ethyl acetate, butylacetate, butyl alcohol, amyl alcohol or benzene, and the shaken liquoris allowed to stand still. When the liquor is separated into two layers,the upper layer is collected. This procedure is repeated twice or threetimes, and the collected upper layers are combined. The combined liquoris concentrated to obtain an oily impure substance. This impuresubstance is purified to colorless crystals by the following columnadsorption chromatography.

Silica gel having a size of 70 325 mesh is packed in a column by the useof benzene. and the above oily impure substance is adsorbed on top ofthe silica gel column, and then eluted with ethyl acctatecontainingbenzene while increasing the ethyl acetate concentration gradually.Thus. colorless needle crystals of 2,2- dihydroxy-3,S-dimethoxybibenzyland 3,3-dihydroxy- S-methoxy-bibenzyl can be obtained at ethyl acetateconcentrations of 3 4% and 6 10%, respectively.

Instead of silica gel, there may be employed alumina. magnesia and thelike as a column filler. Such mixed solvents as benzene-methanol,benzene-ethanol, chlo roform-ethyl acetate. chloroform-methanol andchloroform-ethanol can be used as eluting solvents as well asbenzene-ethyl acetate.

In addition to the above-mentioned column adsorption chromatography, itis possible to employ effectively the partition column chromatography inwhich silica gel or Sephadex is used as a support of the stationaryphase. In this case, the lower layer of a n-hexane-methanol (1 1 volumeratio) or n-hexane-ethyl acetate-methanoLwater (2 2 2 I volume ratio)mixture is used as thestationary phase and the upper layer thereof isused as the mobile phase, and thus the devel oping elution is conducted.

We have designated the above two novel compounds inclusively asbatatasin, of which physical and chemical properties are as follows:

2,2'-Dihydroxy-3,S-dimethoxybibenzyl l Molecular weight: 274 (2)Molecular fonnula: C H O (3) Melting point: 48 50C (4) Ultravioletabsorption spectrum:

Maximum absorption (mm) Molecular ahsorhance 282 (shoulder) a 3.07 X10'' 275 6 3.70 X 10' 210 e 3.95 X10 (5) Infrared absorption spectrum:

Maximum absorption. cm

3400, Z940. 2840. I596, I514, I458. 1-132. I358. I236. I204, I170.ll-ll. I095. I046. 996. R30. 755

(6) Nuclear magnetic resonance spectrum:

8 value in heavy chloroform 7.06 2H multiplet 6.90 l H quadruplet 6.761H quadruplet 6.49 IH doublet 6.24 l H doublet 5 .70 l H singlet 4.60 lHsinglet 3.87 3H singlet 3.79 3H singlet 3.85 4H singlet (7) Crystalform: colorless needles 8. Solubility: Soluble in ordinary solvents suchas ethanol, acetone, ethyl acetate and ether. but insoluble in hexaneand water.

9. Color reaction: Negative to 2,4-dinitrophenyl hydrazine butexhibiting a scarlet color to vanillin. l0. Rf value: 0.44 (measured bysilica gel thin layer chromatography employing chloroform/acetic acid of/5 volume ratio) 3 .3 '-Dihydroxy-5methoxybibenzyl (I) Molecular weight:244.1 (2) Molecular formula: C, -,H ..O;, (3) Melting point: 93.5 945C(4) Ultra\ iolet spectrum:

In ethanol Spectral characteristics under neutral and hydrochloricacid-acidifying conditions are as follows:

Maximum adsorption (mm) Molecular absorhance 2x1 5 mix 276 6 0.34 X 10*223 11.29 x10 Spectral characteristics under alkaline conditions withaddition of KOH of 0.005 N are as follows:

Maximum adsorption (mm) Molecular ahsorbance 292 10.46 X 10 283 610.42 X10 (shoulder) Infrared adsorption spectrum:

Maximum adsorption. cm

3340, I620. I600. I450. H90. H50. 1055, 980, 940. 690

(6) Nuclear magnetic resonance spectrum:

8 value in heavy chloroform 7. l4 triplet 6.78 singlet 6.66 multiplet 56.26 multiplet 3.74 singlet 2.82 singlet 7. Crystal form: colorlessneedles 8. Solubility: Soluble in ordinary solvents such as ethanol,acetone, ethyl acetate and ether, but difficulty soluble in water andinsoluble in hexane.

9. Color reaction: Negative to 2,4-dinitrophenyl hydrazine butexhibiting an orange red color to vanillin.

l0; Rf value: 0.20 (measured by silica gel thin layer chromatographyusing chloroform/acetic acid of 95/5 volume ratio) This novel substance,batatasin, exhibits a very 40 high effect of controlling the growth orgermination in plants. Therefore, the activity of this substance can bedetected by the biological test as follows:

Buds of a terrestrial tuber of a yam (Dioscurea bamms Decne.) or that ofa subterranean tuber of a potato which have awakened from hibernationare cut out in the cylindrical form by means of a cork borer. A filterpaper or absorbent cotton containing an aqueous solution of a sample tobe tested is placed in a culture dish, and the cut-out buts arearrangedon the filter paper or absorbent cotton. Cultivation is carried out inthis state at about 25C for 1 2 weeks, and the degree of inhibition ofgermination is observed.

Alternately, it ispossible to examine by a method comprising sowingseeds of a lettuce (Lac-Inca saliva L.) or a rice plant on a culturedish arranged in the same manner as described above, conductingcultivation at 23C for 2 3 days and observing the germination state.Moreover, it is possible to examine by a way wherein seeds of oats(Arena saliva L.),areallowed to germinate under weak red light, and 3days after sowing, a sectin of 5 mm in length is cut from a coleoptileof about 25 mm in length. Sections thus prepared are floated on aculture medium prepared bydissolving a sample to be tested in an aqueoussolution containing 0.1 mg/l of indoleacetic acid, 0.05% of Tween 20 and2% of sucrose. Cultivation is continued for 18 hours at 6 25C in thedark. Then,'the detection can be made basedon inhibition of growth ofthe coleoptile sections.

Further a chemical detection method. which utilize a color reaction withvanillin'sulfuric acid can be used. According to this method, a sampleto be tested is placed in a thin layer plate of Silica Gel G (product ofMerk Co.) and is developed with chloroform-acetic acid (/5 volumeratio). Then a vanillin-sulfuric acid reagent is sprayed to the sampleand the plate is heated at C for about 5 minutes. Thus, the above novelsubstances are detected as scarlet and orange red spots. respectively.

As described above. the plant growth modifier of this inventioncomprises at least one compound selected from the group consisting ofcompounds expressed by the above general formulae (I),( II) and (III).These active ingredient compounds can be applied directly as they are.Still further, they can be applied in the form of various formulationsadopted in the agricultural field. For instance, they are formed intovarious agricultural formulations such as dusts, wettable powders,emulsions and granules by blending with solid or liquid carriers,diluents, developers, dispersants and other adjuvants. Further. theyexhibit their activities at any concentration or application ratevarying in very broad range. Therefore, the concentration andapplication rate can be selected and decided appropriately depending onthe object of application.

Moreover, the plant growth modifier of this invention can be used incombination with other plant growth modifiers, fungicides, insecticidesor fertilizers according to need, whereby a variety of agriculturalapplication can be attained.

This invention will now be illustrated by reference to Examples showingthe preparation of agricultural formulations and the utility of theplant growth modifier of this invention, but this invention is notlimited to these Examples. In Examples all of *parts" are on a weightbasis.

EXAMPLE 1 0.02 part of 3-hydroxy5-methoxybibenzyl was mixed with 99.98parts of clay, and the mixture was ground to obtain dusts.

EXAMPLE 2 2 parts of 2,4-dimethoxy-6-hydroxyphenanathrene, 20 parts ofTween 20 (surfactant manufactured by Atlas Chemical Co., U.S.A.), 30parts of acetone and 48 parts of water were mixed together to obtain awettable powder.

EXAMPLE 3 2 parts of 7-hydroxy-2,6-diacetyl-9.l0-dihydrophenanthrene, 4parts of glycol ether and 94 parts of methanol were mixed together-toobtain an emulsifiable liquor.

The utility of the plant growth modifier of this invention will beillustrated below.

EXAMPLE 4 A compound illustrated in Table l was dissolved indimethylformamide and the solution was diluted to desired concentrationswith water containing 2% of su- 7 crose. In control testdimethylformamide was applied in the same amount as that of treatedgroups. This solvent gives no phytotoxicity to plants to be tested ifthe Table 2 Inhibition ot'Germin-ation of Lettuce Seeds a r content inwater is l/c or less. The prepared liquors cumpmmd Concentration(,ug/ml) were poured into culture dishes of 3 cm diameter. the GivingInhibition amount of the medium poured into one dish being 2 ml. 1Sections of 5 mm in length cut from a coleoptiles of 3 3 1211 oats(Aunt! .suma L.) which have been grown in the 4 90 dark were floated onthe test media in the culture 5 911 dishes and cultured at C for 20hours in the dark to 10 determine the growth-inhibition degrees. Resultsare 1 xi; shown in Table l. 9 m0 1 1 In the control group, thecoleoptile elongated by 8:, about 5 mm during the experiment. 12 140Table 1 Growth Inhibition in oats coleoptile C p (concentration gi\- No.Active Ingredient Melting ing 50% inhibition Point( C) lug/nth) 3'hdroxySmcthoxybibenzyl 50-52 81) Z 2.2'dihydroxy-3.5climethox 48-50 101)hihenzyl 3.4'-dihydroxy4.i -tlimetho q 128-130 150 hihenz l lfi-dihvdrox}-3-acetyldihenzyl 136 90 5 ZA-dihydroxyhihenql 137-138 l ll)3.5.3'.5-tetrachloro-2.2- 203-204 dihydroxybibenzyl 7 3.3 .5'-trihydroxy-4-methox 135-136 75 hibenzyl 83.3"dilndrosyS-methoxyhibenzyl 93.5-94.5 IOU 9 Z.4-dimethoxy o-hydroxy-135 130 phenanthrene 11) 4-h vdroxy-2.6.7-trimethoxy- 148- l 49phenanthrene l l 2.6dihydroxy-3.4.7 trimetho 1y 297-300 100 phenanthrenel2 4.6.7'trihydroxy-Z.3-dimethoxy- 155-156 .131)

phenanthrene l3 Z.4-dimethox fi-h droxyphenan- I 90 threne 1-16chloro-9-acetylphenanthrene 139-140 70 15 7-h droxy-Zb-diacetyl-J.10-155 13k) dih \drophenanthrene l6 3.3.5.7-tetrahydroxy-9.lO-di- 291-292150 hydrophenamhrene l7 4.7-dihydroxv-Zj.6-trimethoxy' 147-150 But] 9.l1l-dihydrophenanthrene 18 4.7-dihydroxylfi-dimethox 128-130 18119.lU'dihydrophenanthrene 13 x11 1 14 311 15 so EXAMPLE 5 16 W)Everycompound shown in Table l was respectively dissolved at variousconcentrations in distilled water containing 1% of dimethylformamide,and 3 ml each of the resulting solutions was poured into a culture dishof 6 cm diameter in which 2 filter papers were spread. EXAMPLE 6 {Aboutsemis W-1 a i z i Bulbils (fleshy buds for breeding formed on stems) off i h" i 5%. g yarn (Dioscorea bamrus Decne.) were stored at a low i d tc f to Stan t E 5 temperature of 5C for 3 months and awakened from l ipercemdgs weref immune hibernation. These fleshy buds were treated withthe p g t e g l g O t e p agricultural chemical of this invention in thefollowing s- 7 Q L b P 5 d {EE S E Q P z, manner to lead them tohibernation again. C m l 1 g f fi 1 e T Q Every active ingredientcompound of this invention lbmon rate gwen m t e O owmg shown in thefollowing Table 3 was dissolved emulsified in distilled water containing1% of dimethylformamide gsrminfllifln Percsnmgc of "811ml and 0.5% ofTween 20V 25 ml of the resulting liquor was Percemug poured into aculture dish of 9 cm diameter in which absorbent cotton was spread. and30 of bulbils which Usually the germination percentage of the untreatedcontrol lot was about Results are shown in Table had beensubjected tothe above low temperature treatment and awakened from dormancy were sownon the dish and they were allowed to sprout at 23C under 9 light of 1800luxes for 2 weeks. As a result ofexamination of the sprouting state. itwas confirmed that the active ingredient compound of this inventionexhibited. as shown in Table 3. a prominent action of inhibitinggermination. i.e., a high dormancy-inducing activity.

4-Hydroxy-2,6.7trimethoxyphenanthrene and 3,3-dihydroxy-Smethoxybibenzyl were respectively dissolved at variousconcentrations in water containing 0.05% of Tween 20, and 30 ml each ofthe resulting solutions were poured into culture dishes of 9 cm indiameter containing 1 g of absorbent 'cotton.

Thirty bulbils of yam (Discora batatas Decne.) which had been awakenedfrom dormancy were planted in each of the arranged culture dishes, andthe germination test scarried out at 23C either in the dark or in thelight. Data of the sprouting obtained after 20 days cultivation areshown in Table 4, from which it is seen that the above two compoundsexhibited a high sprouting-inhibiting activity.

Table 4 Concentration Sprouting Ratio Compound (mg/ dark light placeplace 4-hydroxy-2.6.7-tri- 100 46' 14 methoxyphenanthrene same as above300 30 8 same as above 1000 23 3,3-dihydroxy-5- 100 S6 23methoxybibenzyl same as above 300 22 I8 same as above 1000 14 untreatedcontrol 0 56 44 The inhibition of sprouting attained by the abovechemical treatment was completely relieved by subjecting the tuber to alower temperature treatment at 4C for additional 1 month, and nophytotoxicity was found.

EXAMPLE 8 4-Hydroxy-2,6,7-trimethoxyphenanthrene and 3,3-dihydroxy-S-methoxybibenzyl were respectively dissolved in watercontaining 0.05% of Tween and 1% of dimethylformamide. and each of theresulting solution was poured into a culture dish. 6 cm in diameter, inwhich 2 layers of filter paper were spread to form a germination bed.100 seeds of a lettuce Lacrucu saliva L.) were sown on the germinationbed and cultivation was conducted for 2 days at 23C. Results ofexamination on the germination ratio are shown in Table 5, from which itis seen that these compounds exhibited a germination-inhibitingactivity.

The number of seeds germinated ln'lil) ratio germ t n The number ofseeds sown Germination-inhibited seeds was not blighted but when theywere washed with water and transplanted on a culture dish free of4-hydroxy-2,6.7-trimethoxyphenanthrene or3,3-dihydroxy-5-methoxybibenzyl, they showed complete germination.

EXAMPLE 9 Oats (Avena sativa L.) were allowed to germinate under a weakred light at 25C and 3 days after germination sections of 5 cm in lengthwere cut from coleoptiles about 25 mm in length.4-Hydroxy-2.6.7-trimethoxyphenanthrene or3,3'-dihydr0xy-S-methoxybibenzyl was dissolved in a culture mediumcomprising 0.1 t'ng/l of indoleacetic acid. 0.05% of Tween 20 and 2% ofsucrose, the balance being water. Ten of the above cut-out coleoptilepieces were flated on the re sulting culture medium and cultivation wasconducted at 25C for 18 hours to examine the growth state and theresdlts shown in Table 6 were obtained. From the table 'it' is seen thatthe above compounds exhibited a growthinhibiting activity.

(Length of untreated control sections)- (lnitial length of sections)EXAMPLE l0 4-Hydroxy-2.6,7-trimethoxyphenanthrene or 3.3-dihydroxy-S-methoxybibenzyl was dissolved in acetone. and the resultingsolution was placed in culture dishes in which 2 layers of filter paperwere spread so as to give required amounts of the test compound. Afterthe acetone was removed by evaporation. Hoaglands nutrient solutioncontaining 0.05% of Tween 20 was poured into the culture dishes.Seedings of lettuce 1 l (Lat-mm sum-a L.) which had been germinated in adifferent place, were transplanted to the culture dishes and cultivationwas carried out in a light place at 23C for 3 days. Then the lengths ofthe stems (hypocotyls) were measured to determined the growth inhibitionra tio. Results are shown in Table 7.

untreated control (I U What we claim is:

1. A composition useful for inhibiting the growth and germination ofhigher plants which comprises as the active ingredient an effectiveamount of Z T-dihydroXy- 3.5-dimethoxybibenzyl or 3 ,3dihydroxy-S-methoxybibenzyl in combination with an inert solid or liquiddiluent or carrier.

2. The composition of claim 1 in which the carrier is aqueousdimethylformamide.

3. The composition of claim 1 in which the carrier is aqueousdimethylformamide containing 27: sucrose.

4. The composition of claim 2 in which the carrier is distilled watercontaining a 1% solution of a dimethylformamide.

5. The composition of claim 1 wherein the active ingredient is2,2'dihydroxy-3,S-dimethoxybibenzyl.

6. The composition of claim 1 wherein the active ingredient is3.3-dihydroxy-S-methoxybibenzyl.

7. A method for inhibiting the growth and germination of higher plantswhich comprises applying thereto an effective amount of a bibenzylcompound of the formula:

wherein X and Y are the same or different members selected from chloro,hydroxy, methoxy or acetyl; and m and n are integers having a value offrom O to 3.

8. The method according to claim 7 wherein the bibenzyl compound is3-hydroxy-5-methoxybibenzyl; 2.2'-dihydroxy-3,S-dimethoxybibenzyl;3,4'-dihydroxy-4.5-dimethoxybibenzyl; 4,6-dihydroxy-3-acetyldibenzyl;2.4-dihydroxybibenzyl; 3 5.3',5-tetrachloro- 2,2'-dihydroxybibenzyl;3,3,5-trihydroxy-4-methoxybibenzyl; or 3,3-dihydroxy-S-methoxybibenzyl.

9. The method according to claim 7 wherein the bibenzyl compound is incombination with an inert solid or liquid carrier or diluent.

10. The method of claim 7 wherein the bibenzyl compound is3-hydroxy-5-methoxybibenzyl.

11. The method of claim 7 wherein the bibenzyl compound is2,2'-dihydroxy-3,S-dimethoxybibenzyl.

12. The method of claim 7 wherein the bibenzyl compound is3,4-dihydroxy-4,5-dimethoxybibenzyl.

13. The method of claim 7 wherein the bibenzyl compound is4,6-dihydroxy-3-acetyldibenzyl.

14. The method of claim 7 wherein the bibenzyl compound is2,4-dihydroxybibenzyl.

15. The method of claim 7 wherein the bibenzyl compound is 3.5,3',5-tetrachloro-2,2-dihydroxybibenzyl.

16. The method of claim 7 wherein the bibenzyl compound is 33,5'-trihydroxy-4-methoxybibenzyl.

17. The method of claim 7 wherein the bibenzyl compound is3,3-dihydroxy-methoxybibenzyl.

4 UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTIONPATENT NO. 3,917,477 Q DATED November 4, 1975 VENTOMS) I TOHRU HASHIMOTOET AL It is certified that error appears in the above-identified patentand that said Letters Patent are hereby corrected as shown below;

In the Abstract and in column 1, Formulas II and III should read asfollows:

Xn Xn r (II) (I Ym Ym Signed and Sealed this- Q [SEAL] Twenty'fifst D yf September 1976 Arrest:

RUTH c. MASON c. MARSHALL DANN Anemng 011m) s m vj'lfarenrs andTrademarks UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OFCORRECTION PATENT N0. 3,917,477 DATED November 4, 1975 NTOR(S) TOHRUHASHIMOTO ET AL It is certified that error appeeirs in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

In the Abstract and in column 1, Formulas II and III should read asfollows:

Xn Xn (II) (III) Ym Ym g and Scaled this [SEAL] Twsnty'first D fSeptember 1976 A ttes I:

:UTH C. MAHSON C. MARSHALL DANN treslmg Officer Commissioner ujParentsand Trademarks

1. A COMPOSITON USEFUL FOR INHIBITING THE GROWTH AND GERMINATION OFHIGHER PLANTS WHICH COMPRISES AS THE ACTIVE INGREDIENT AN EFFECTIVEAMOUNT OF 2,2''-DIHYDROXY-3,5-DIMETHOXYBIBENZYL OR3,3''-DIHYDROXY-5-METHOXYBIBENZYL IN COMBINATION WITH AN INERT SOLID ORLIQUID DILUENT OR CARRIER.
 2. The composition of claim 1 in which thecarrier is aqueous dimethylformamide.
 3. The composition of claim 1 inwhich the carrier is aqueous dimethylformamide containing 2% sucrose. 4.The composition of claim 2 in which the carrier is distilled watercontaining a 1% solution of a dimethylformamide.
 5. The composition ofclaim 1 wherein the active ingredient is2,2''-dihydroxy-3,5-dimethoxybibenzyl.
 6. The composition of claim 1wherein the active ingredient is 3,3''-dihydroxy-5-methoxybibenzyl.
 7. Amethod for inhibiting the growth and germination of higher plants whichcomprises applying thereto an effective amount of a bibenzyl compound ofthe formula:
 8. The method according to claim 7 wherein the bibenzylcompound is 3-hydroxy-5-methoxybibenzyl;2,2''-dihydroxy-3,5-dimethoxybibenzyl;3,4''-dihydroxy-4,5-dimethoxybibenzyl; 4,6-dihydroxy-3-acetyldibenzyl;2,4-dihydroxybibenzyl; 3,5,3'',5''-tetrachloro-2,2''-dihydroxybibenzyl;3,3'',5''-trihydroxy-4-methoxybibenzyl; or3,3''-dihydroxy-5-methoxybibenzyl.
 9. The method according to claim 7wherein the bibenzyl compound is in combination with an inert solid orliquid carrier or diluent.
 10. The method of claim 7 wherein thebibenzyl compound is 3-hydroxy-5-methoxybibenzyl.
 11. The method ofcLaim 7 wherein the bibenzyl compound is2,2''-dihydroxy-3,5-dimethoxybibenzyl.
 12. The method of claim 7 whereinthe bibenzyl compound is 3,4''-dihydroxy-4,5-dimethoxybibenzyl.
 13. Themethod of claim 7 wherein the bibenzyl compound is4,6-dihydroxy-3-acetyldibenzyl.
 14. The method of claim 7 wherein thebibenzyl compound is 2,4-dihydroxybibenzyl.
 15. The method of claim 7wherein the bibenzyl compound is 3,5,3'',5=-tetrachloro-2,2''-dihydroxybibenzyl.
 16. The method of claim 7wherein the bibenzyl compound is 3,3'',5''-trihydroxy-4-methoxybibenzyl.
 17. The method of claim 7 wherein thebibenzyl compound is 3,3''-dihydroxy-5-methoxybibenzyl.